1. Field of the Invention
The present invention relates to a holder support device for supporting various holders, such as specimen holders and aperture holders, used in apparatus making use of a charged-particle beam, such as an electron microscope.
2. Description of Related Art
A holder support device for supporting a specimen holder for use with an electron microscope, or the like, is described in Japanese patent laid-open No. 2000-268758, where the holder support member, indicated by numeral 23, extends through the microscope column (outer wall) of the microscope and has a cylindrical wall 24. This wall 24 has a slider-receiving groove 24c in its outer-end portion. The groove 24c accommodates a guide pin H4 on the specimen holder H and a slider 51. The holder H is mounted on the cylindrical wall 24. Atmospheric pressure acting on the outer end of the holder H urges it toward its inner end. A holder inner end-positioning drive mechanism (X-position adjustment device) bearing against the inner end of the holder H places it in position along the axis of the holder.
The above-cited Japanese laid-open publication also describes a spring 63 for preventing the slider 51 from moving toward the inner end to alleviate the pressure applied on the holder inner-end positioning mechanism (X-position adjustment device) by the specimen holder H, which, in turn, is pushed toward the inner end by atmospheric pressure. The guide pin H4 on the holder H engages the slider 51.
U.S. Pat. No. 5,581,088 (corresponding to Japanese patent laid-open No. 124508/1996) also describes a specimen holder (holder support device) in which a specimen-holding rod (holder) 22 fitted with a pin 27 for opening and closing a partition valve 10 is held to a third pipe 17. The specimen holder has an X drive means 30 for adjusting the position of the specimen-holding rod 22 that moves together with the third pipe 17 in the X-axis direction, by controlling the X-position of a shaft 56 mounted to the third pipe 17.
In the technique of the above-cited Japanese patent laid-open No. 2000-268758, the pressure applied to the X-position-adjusting device (inner-end positioning mechanism) is alleviated and so accurate adjustment of the position of the specimen holder H is permitted. The X-position adjusting device is mounted on the outer wall (microscope column) on the opposite side of the holder support device. In the case of a transmission electron microscope, therefore, the space formed around the specimen holder and permitting installation of other attachments, such as observational instrument and analytical instrument, is narrowed.
In the case of an apparatus that needs a large specimen chamber space, such as a scanning electron microscope, X-ray microanalyzer, or focused ion beam (FIB) system, if an X-position adjusting device is mounted on the opposite surface of the holder support device, the distance between the holder support device and the X-position adjusting device will be increased. Therefore, this apparatus is difficult to manufacture.
In the technique of the above-cited U.S. Pat. No. 5,581,088, the X-position adjusting device for placing the specimen holder in position in the X-axis direction is mounted to the holder support device together with other position adjusting devices. Therefore, the problem with the above-cited Japanese patent laid-open No. 2000-268758 does not take place. However, a first pipe 7 and a second pipe 15 are used in addition to the third pipe 17 described above. A bellows 19 is mounted between the second pipe 15 and third pipe 17. The partition valve 10 is opened and closed by the pin 27 of the specimen-holding rod 22. The shaft 56 is mounted to the third pipe 17, and the position of the specimen-holding rod 22 is adjusted. Consequently, the specimen-holding device (holder support device) is complex in structure.
It is an object of the present invention to provide a holder support device which has a detachable cylindrical holder extending along the X-axis, permits adjustment of the X-, Y-, and Z-positions of the inner end of the holder, as well as adjustment of the rotational position about the X-axis, and enables a partition valve to be opened and closed.
This object is achieved by the present invention by a holder support device comprising: a cylindrical support member extending through a specimen chamber wall and mounted to this wall; an outer cylinder inserted in the support member and capable of swinging in the Y- and Z-axis directions about a spherical bearing formed on the inner surface of the support member; an inner cylinder rotatably mounted in the outer cylinder; a holder rotatably mounted in the inner cylinder and made slidable by an X-position adjusting device; a partition valve placed between the inner cylinder and a specimen chamber; and a mechanism for opening and closing the partition valve by rotation of the inner cylinder that is rotated by the holder when the holder rotates.
Other objects and features of the invention will appear in the course of the description thereof, which follows.